Solid Phase Biomass Carbon Storage (SPBCS)

ABSTRACT

A computerized method of using a data processor having a memory to account for carbon flows and determine a regulatory value for a biofuel includes (i) storing, in memory, a first set of one or more carbon flow values characterizing the production and use of a biofuel, wherein the biofuel is derived from a first fraction of an agricultural biomass comprising sugar cane or soybean, (ii) storing, in memory, a second set of one or more carbon flow values characterizing the sequestration of solid phase biomass carbon, wherein the solid phase biomass carbon is derived from a second fraction of the agricultural biomass and wherein the sequestration mitigates anthropogenic greenhouse gas emission, and (iii) calculating, using the data processor, a regulatory value for the biofuel from the first and second sets of carbon flow values.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims benefit of priority to U.S. Ser. No. 13/608,828,filed on Sep. 10, 2012; U.S. Ser. No. 13/192,182, filed on Jul. 27,2011; and U.S. Ser. No. 61/374,953, filed on Aug. 18, 2010, thedisclosures of which are incorporated herein by reference in theirentirety.

FIELD OF THE TECHNOLOGY

The invention relates generally to biofuel production. The inventionrelates more particularly to methods of accounting for carbon flows anddetermining a regulatory value for a biofuel, methods of engineeringcarbon cycles for biofuel production, and methods of manufacturingbiofuels, as well as the biofuels and regulatory values derivedtherefrom.

BACKGROUND OF THE INVENTION

Carbon intensity (CI) is a fuel characteristic that is increasinglybeing measured and regulated in various jurisdictions within the U.S.and abroad (e.g., U.S. RFS2; LCFS in CA, BC, WA, OR, NEMA; EU-RED;UK-RTFO). CI can be used as a measure of net greenhouse gas emissionsfrom across the fuel life cycle generally evaluated using lifecycleanalysis (LCA) methods and specified per unit fuel energy, e.g., inunits of gram CO2 equivalent emissions per mega-joule of fuel(gCO2e/MJ). For biofuels, carbon intensity measures can includeemissions from sources associated with supplying inputs for agriculturalproduction (e.g., fertilizers), fuel combustion, and certain or allprocess steps in between, which may be used to define a fuel productionpathway, or simply a fuel pathway. LCA of carbon intensity can be set upas an accounting system with emissions to the atmosphere (e.g.,combustion emissions) representing LCA accounting debits and flows fromthe atmosphere (e.g., carbon fixed from the atmosphere viaphotosynthesis) representing LCA accounting credits. The sign conventioncan be reversed relative to financial accounting, but this is how theterms are often used in practice.

SUMMARY OF THE INVENTION

LCA methods can be used to assess a variety of social and environmentalperformance characteristics of biofuels, which can collectively bereferred to using the term sustainability. Biofuel sustainabilitycharacteristics or sustainability performance can be reflected withinbiofuel and related policy instruments (e.g., as a quantitative valueassociated with, or characterizing, the biofuel, as well as relatedstandards), to provide a framework for avoiding potential negativeconsequences of expanding biofuel production.

The effects of biomass carbon that is not converted into biofuel orother products (e.g., agricultural and biofuel production residues) canbe reflected in evaluations of biofuel/product performance againstsustainability metrics in methods similar to those used for carbonintensity measures. In other words, LCA can reflect emissions creditsand debits accrued across the whole fuel production pathway or supplychain, including emissions effects of biomass carbon not converted intouseful products. This can be accomplished by providing a lifecycleemissions accounting credit to the product of interest based onallocation of a fraction of lifecycle emissions (generally emissionsassociated with processes upstream of the material diversion forco-product/by-product use) to the various products (according to socalled “allocation” accounting methodologies) or by providing lifecycleemissions accounting credits (or debits) for net emissions reductions(or increases) associated with use of the variousco-products/by-products relative to use of more conventional products(according to so called “system expansion” accounting methodology).

Solid phase biomass carbon storage (SPBCS) provides systems, methods,and processes for sequestering solid phase carbon in biomass away fromthe atmosphere for time periods appropriate for mitigating anthropogenicgreenhouse gas emissions. The biomass could remain in the SPBCS storagesystems indefinitely, or could be reprocessed into products that providecontinued sequestration benefits (e.g., building materials), into energyproducts with continued carbon sequestration benefits via CO2 captureand storage (CCS), or into energy products without CCS with emissionsbenefits from bio-energy substitution for conventional products (e.g.,from fossil fuels), but at the expense of carbon sequestration benefits.In the latter scenario, climate benefits associated with deferredemissions would still be realized. Thus, SPBCS enables presentrealization of carbon benefits associated with biomass materials,specifically benefits associated with preventing the degradation of suchmaterials, which would result in the release of biomass carbon to theatmosphere as greenhouse gases, and potential future realization ofpotential chemical or energy benefits of sequestered biomass carbon.SPBCS also operates within the context of various regulatory systems,enabling the environmental benefits to be quantified and associated witha biofuel or a tradable credit. Such tradable credits can be distinctfrom LCA accounting credits, in that they may be specifically traded(bought or sold) under certain regulatory frameworks. Thus, SPBCS alsocan provide an economic incentive, which would not have existed prior tothe implementation of such regulatory systems, for affectingenvironmental objectives.

In one aspect, the invention provides a computerized method of using adata processor having a memory to account for carbon flows and determinea regulatory value for a biofuel. The method includes (i) storing, inmemory, a first set of one or more values characterizing carbon flowsassociated with the production and use of a biofuel, wherein the biofuelis derived from a first fraction of an agricultural biomass, (ii)storing, in memory, a second set of one or more values characterizingcarbon flows associated with the sequestration of solid phase biomasscarbon, wherein the solid phase biomass carbon is derived from a secondfraction of the agricultural biomass and wherein the sequestrationmitigates anthropogenic greenhouse gas emission, and (iii) calculating,using the data processor, a regulatory value for the biofuel from thefirst and second sets of carbon flow values.

In another aspect, the invention provides a method of engineering acarbon cycle for biofuel production and use. The method includes (i)arranging the production of a biofuel from a first fraction of anagricultural biomass and the sequestration of solid phase biomass carbonfrom a second fraction of the agricultural biomass, which mitigatesanthropogenic greenhouse gas emission and (ii) assigning a regulatoryvalue to the biofuel from a first set of one or more carbon intensityvalues characterizing the production and use of the biofuel, and asecond set of one or more carbon intensity value characterizing thecarbon sequestration.

In yet another aspect, the invention provides a method of manufacturinga biofuel. The method includes (i) producing a biofuel from a firstfraction of agricultural biomass, (ii) sequestering solid phase biomasscarbon from a second fraction of the agricultural biomass, whereinsequestration mitigates anthropogenic greenhouse gas emission, and (iii)assigning a biofuel a regulatory value based upon a first set of one ormore carbon intensity values characterizing the production and use ofthe biofuel and a second set of one or more carbon intensity valuecharacterizing the sequestration.

In still another aspect, the invention provides a computerized method ofusing a data processor having a memory to account for carbon flows anddetermine a regulatory value for a biofuel. The method includes (i)storing, in memory, a first set of one or more carbon flow valuescharacterizing the production and use of a biofuel, wherein the biofuelis derived from a first fraction of an agricultural biomass, (ii)storing, in memory, a second set of one or more carbon flow valuescharacterizing the sequestration of solid phase biomass carbon, whereinthe solid phase biomass carbon is derived from a second fraction of theagricultural biomass including agricultural residue and wherein thesequestration mitigates anthropogenic greenhouse gas emission, (iii)calculating, using the data processor, a regulatory value for thebiofuel from the first and second sets of carbon flow values, and (iv)trading the biofuel having the regulatory value, a tradable creditgenerated as a function of the regulatory value, or both the biofuel andthe tradable credit. The sequestration includes processing to mitigatedegradation of the solid phase biomass carbon and storing the solidphase biomass carbon to mitigate environmental interaction.

In still another embodiment, the invention provides a method ofengineering a carbon cycle for biofuel production and use. The methodincludes (i) arranging the production of a biofuel from a first fractionof an agricultural biomass and the sequestration of solid phase biomasscarbon from a second fraction of the agricultural biomass includingagricultural residue, thereby mitigating anthropogenic greenhouse gasemission, (ii) assigning a regulatory value to the biofuel from a firstset of one or more carbon intensity values characterizing the productionand use of the biofuel, and a second set of one or more carbon intensityvalue characterizing the sequestration, and (iii) trading the biofuelhaving the regulatory value, a tradable credit generated as a functionof the regulatory value, or both the biofuel and the tradable credit.The sequestration includes processing to mitigate degradation of thesolid phase biomass carbon and storing the solid phase biomass carbon tomitigate environmental interaction.

In still another embodiment, the invention provides a method ofmanufacturing a biofuel. The method includes (i) producing a biofuelfrom a first fraction of an agricultural biomass, (ii) sequesteringsolid phase biomass carbon from a second fraction of the agriculturalbiomass including agricultural residue, wherein sequestration mitigatesanthropogenic greenhouse gas emission, (iii) assigning the biofuel aregulatory value based upon a first set of one or more carbon intensityvalues characterizing the production and use of the biofuel and a secondset of one or more carbon intensity value characterizing thesequestration, and (iv) trading the biofuel having the regulatory value,a tradable credit generated as a function of the regulatory value, orboth the biofuel and the tradable credit. The sequestration includesprocessing to mitigate degradation of the solid phase biomass carbon andstoring the solid phase biomass carbon to mitigate environmentalinteraction.

In still another aspect, the invention provides a method including (i)receiving a biofuel feedstock produced from a first fraction of anagricultural biomass, wherein the biofuel feedstock has associatedsequestered solid phase biomass carbon, wherein the solid phase biomasscarbon is derived from a second fraction of the agricultural biomass andwherein the sequestration mitigates anthropogenic greenhouse gasemission and (ii) producing a low carbon fuel derived from the biofuelfeedstock, wherein the low-carbon fuel comprises a transportation fuelhaving a LCA carbon emissions accounting credit based at least in parton a fuel pathway comprising the sequestration of the solid phasebiomass carbon.

In still another aspect, the invention provides a method including (i)receiving a biofuel produced from a first fraction of an agriculturalbiomass, wherein the biofuel has associated sequestered solid phasebiomass carbon, wherein the solid phase biomass carbon is derived from asecond fraction of the agricultural biomass and wherein thesequestration mitigates anthropogenic greenhouse gas emission and (ii)providing the biofuel as a low carbon biofuel, wherein the low-carbonbiofuel comprises a transportation fuel having a LCA carbon emissionsaccounting credit based at least in part on a fuel pathway comprisingthe sequestration of the solid phase biomass carbon.

In still another aspect, the invention provides a method of sequesteringbiomass produced within a biofuel supply chain, but not converted into abiofuel, to reduce anthropogenic greenhouse gas emissions, such thatresulting reductions in anthropogenic greenhouse emissions can beassigned to the biofuel supply chain or biofuel produced in the biofuelsupply chain.

In still another aspect, the invention provides a method of providing abiofuel having a reduced carbon intensity value by (i) purchasing abiofuel produced from a first fraction of biomass, wherein the biofuelhas associated sequestered solid phase biomass carbon, wherein the solidphase biomass carbon is derived from a second fraction of theagricultural biomass and wherein the sequestration mitigatesanthropogenic greenhouse gas emission, (ii) assigning a carbon intensityvalue that reflects a LCA emissions accounting credit for mitigatinganthropogenic greenhouse gas emissions, and (iii) selling at least oneof the biofuel and a tradable credit defined as a function of the carbonintensity value.

In still another aspect, the invention provides a method of providing abiofuel having a reduced carbon intensity value by (i) purchasingfeedstock for biofuel production that represents a first fraction of anagricultural biomass, wherein the biofuel has associated sequesteredsolid phase biomass carbon, wherein the solid phase biomass carbon isderived from a second fraction of the agricultural biomass and whereinthe sequestration mitigates anthropogenic greenhouse gas emission, (ii)assigning a carbon intensity value that reflects a LCA emissionsaccounting credit for mitigating anthropogenic greenhouse gas emissions,and (iii) and selling at least one of the biofuel and tradable creditdefined as a function of the carbon intensity value.

In still another aspect, the invention provides for biofuels,sequestered solid phase biomass, and/or tradable credits producedaccording to any of the methods of the invention.

In various embodiments, the sequestration includes processing tomitigate degradation of the solid phase biomass carbon. The processingcan include one or more of collection, drying, resizing, sterilization,stabilization, packaging, and scaling.

In some embodiments, the sequestration includes storing the solid phasebiomass carbon to mitigate environmental interaction.

In certain embodiments, the method also includes monitoring carbon flowfrom the sequestered solid phase biomass carbon.

In various embodiments, the method also includes repurposing thesequestered solid phase biomass carbon.

In some embodiments, the method also includes trading the biofuel havingthe regulatory value, a tradable credit generated as a function of theregulatory value, or both the biofuel and the tradable credit. A methodcan include completing a transaction to sell a low carbon fuel to atransportation fuel provider.

In certain embodiments, the second fraction includes an agriculturalresidue.

In various embodiments, the greenhouse gas emission comprises carbonemission. In general, greenhouse gas can include any one or more gassesthat in the atmosphere absorbs and emits radiation within the thermalinfrared range. Greenhouse gas emission can include, for example, theemission of any one or more of: carbon dioxide, methane, nitrous oxide,and ozone.

It is understood by those skilled in the art that the various aspectsand features described herein can be adapted and combined with thevarious embodiments of the invention. The advantages of the technologydescribed above, together with further advantages, may be betterunderstood by referring to the following description taken inconjunction with the accompanying drawings. The drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles of the technology.

DESCRIPTION OF THE DRAWINGS

FIGS. 1-4 show biogenic carbon flows in different examples of theproduction and use of corn ethanol.

FIGS. 5 and 6 show example process schematics for lifecycle emissionsaccounting.

The invention will now be described in detail with respect to thepreferred embodiments and the best mode in which to make and use theinvention. Those skilled in the art will recognize that the embodimentsdescribed are capable of being modified and altered without departingfrom the teachings herein.

DETAILED DESCRIPTION OF THE INVENTION

SPBCS enables present realization of environmental benefits associatedwith the reduction of greenhouse gas emissions in biofuel carbon cycles.For example, SPBCS can mitigate anthropogenic greenhouse gas (GHG)emissions by providing for biofuels that have a lower carbon intensitythan conventional biofuels and/or conventional fossil hydrocarbon fuels.Additionally, SPBCS operates within the context of various regulatorysystems, enabling the environmental benefits to be quantified andassociated with a biofuel or a tradable credit. Thus, SPBCS can alsohelp provide an economic incentive for providing environmental benefits.

SPBCS represents a unique alternative and an advance when compared toother approaches to mitigating anthropogenic greenhouse gas emission,including production of low carbon fuels and carbon sequestration. Forexample, carbon capture and storage (CCS) represents a set oftechnologies capable of concentrating, compressing, transporting (asnecessary), and sequestering CO2 (e.g., from industrial processes) awayfrom the atmosphere (e.g., in geologic formations). SPBCS differs fromCCS, for example, in that SPBCS involves sequestration of solid phasebiomass carbon, not CO2. SPBCS also differs from other approaches forsequestering carbon (e.g., (i) application of biochar as a soilamendment to increase soil carbon storage and soil fertility and (ii)sinking raw biomass in river deltas where it would be buried in thesediments of alluvial fans). SPBCS differs from such approaches, forexample, because SPBCS can include processing and/or controlled storageand/or use of the solid phase biomass carbon to limit its degradationand enable ongoing measurement and verification of associated climatebenefits. SPBCS further differs from such approaches in its directassociation via biomass production of (i) biofuels produced from a firstfraction of biomass (biofuel feedstock) and (ii) sequestration ofbiomass carbon from a second fraction of biomass that is produced as aconsequence of biofuel feedstock production. This direct associationenables crediting emissions and other sustainability benefits resultingfrom the sequestered biomass carbon to the biofuel produced, yieldingbiofuel products with reduced carbon intensity and/or improvedperformance against sustainability measures.

Processing and/or storage can control and/or mitigate interactionbetween the solid phase biomass carbon and environmental factors (e.g.,heat, light, air, water, animals, insects, fungi, bacteria, and thelike), which can contribute to the release of GHG from the biomass intothe atmosphere. Thus, SPBCS can help protect the environment from thevarious climate risks associated with the release of GHG. SPBCS can alsohelp protect the environment from the various risks associated withother carbon sequestration methods (e.g., prevent the potentialmobilization of stored carbon, for example, by siltation orsedimentation of surface water bodies from water induced bio-charmobilization).

Moreover, SPBCS has the advantage that the stored carbon can be removedfrom storage and repurposed, for example, when it can be used inproducts or services that continue to prevent atmospheric releases ofstored carbon (e.g., building materials or energy systems with CCS),that otherwise continue to provide climate benefits, when development ofother technologies lessens the climate risks associated with atmosphericrelease of stored carbon (e.g., capture of CO2 directly from theatmosphere), and/or when climate risks are determined to have beenotherwise resolved.

In one aspect, SPBCS provides a method of account for carbon flows anddetermination of a regulatory value for a biofuel. The method includes(i) storing a first set of one or more values characterizing carbonand/or GHG flows associated with the production and use of a biofuel,wherein the biofuel is derived from a first fraction of an agriculturalbiomass, (ii) storing a second set of one or more values characterizingcarbon and/or GHG flows associated with the sequestration of solid phasebiomass carbon, wherein the solid phase biomass carbon is derived from asecond fraction of the agricultural biomass and wherein thesequestration mitigates anthropogenic greenhouse gas emission, and (iii)calculating a regulatory value for the biofuel from the first and secondsets of carbon flow values. The accounting can be implemented, in wholeor in part, by hand and/or by essentially any data processing device,including a personal computer, an electronic device such as a smartphoneor tablet, a customized or purpose-built machine, and the like.

In another aspect, SPBCS features a method of engineering a carbon cyclefor biofuel production and use. The method includes (i) arranging theproduction of a biofuel from a first fraction of an agricultural biomassand the sequestration of solid phase biomass carbon from a secondfraction of the agricultural biomass, thereby mitigating anthropogenicgreenhouse gas emission and (ii) assigning a regulatory value to thebiofuel from a first set of one or more carbon intensity valuescharacterizing the production and use of the biofuel, and a second setof one or more carbon intensity value characterizing the sequestration.

In yet another aspect, SPBCS features a method of manufacturing abiofuel. The method includes (i) producing a biofuel from a firstfraction of an agricultural biomass, (ii) sequestering solid phasebiomass carbon from a second fraction of the agricultural biomass,wherein sequestration mitigates anthropogenic greenhouse gas emission,and (iii) assigning the biofuel a regulatory value based upon a firstset of one or more carbon intensity values characterizing the productionand use of the biofuel and a second set of one or more carbon intensityvalue characterizing the sequestration.

Although SPBCS relates to an entire biofuel carbon cycle, it can becarried out by a single entity executing, arranging for and/or providingfor the execution of the individual steps. For example, the singleentity can contract for the completion of one or more individual steps(e.g., agricultural production, biofuel production, sequestration ofsolid phase biomass carbon, agricultural residue utilization, and/orgreenhouse gas accounting and/or sustainability assessment). In someembodiments, the single entity might employ a preexisting framework orregistration in carrying out the method (e.g., purchase a biofuelfeedstock with an established CI and/or sustainability measurereflecting SPBCS, or produce a biofuel with an established CI and/orsustainability measure reflecting SPBCS) rather than ascertaining valuesfor components of the pathway from scratch. Therefore, although themethod integrates a wide variety of features from a long and complexsupply chain/carbon cycle, the method is readily implemented by a singleentity.

In the context of SPBCS, biomass includes materials derived frombiological processes including, but not limited to: photosynthesis;consumption of photosynthetically produced biomass, such as biomass ofheterotrophic organisms, waste products or residues from heterotrophicorganisms; or products, byproducts, or residues resulting fromindustrial processing of biomass. For illustrative purposes, thedetailed description of the invention will use an example ofagricultural residues resulting from corn production, commonly referredto as corn stover. Corn stover results from corn production in general,but is particularly relevant in the context of ethanol production fromcorn, as emissions associated with the degradation of this corn stoverare or may be treated differently than corn stover from other sourceswithin particular regulatory contexts (e.g., the California Low CarbonFuel Standards and federal Renewable Fuels Standard). The use of thisexample for illustrative purposes in no way limits the applicability ofthis invention to corn stover produced in this supply chain,agricultural residues resulting from biofuel production or toagricultural residues as a class of biomass. A person of ordinary skillin the art can readily apply the example provided to biofuel productionfrom many other feedstock sources, including for example: sugar cane;wheat; sugar beets; soybeans; canola; camolina; and the like.

In various embodiments, other classes of agricultural biomass caninclude, for example: agricultural residues from production of otherbiofuel feedstock types; forestry residues; biomass from land clearingactivities; clippings from landscaping or property maintenance (publicor private); animal solid wastes (e.g., manures); aquatic plant solids;industrial biomass solid residues (e.g., mill wastes, sugar canebagasse, residues from starch or cellulosic biofuels production,lipid-extracted algae, anaerobic digestor solids, etc.); or biomassproduced or harvested specifically for SPBCS (e.g., perennial grasses).

In general, a first fraction of the biomass can be a fraction of thebiomass that is used as a biofuel feedstock (e.g., lipid and/orcarbohydrate rich fraction in the example of a first generationbiofuel). In general, the second fraction of the biomass can be afraction of the biomass that is not used as a biofuel feedstock (though,in some embodiments, the second fraction can also be a biofuelfeedstock, e.g., for a cellulosic biofuel). In various embodiments, thesecond fraction is or comprises an agricultural residue. The termagricultural residues is used here to describe biomass produced inagriculture, silviculture, and or aquaculture systems that is typicallyor historically not of sufficient value to be converted into salableproduct(s) and is therefore historically allowed to decompose in naturalor modified environments (e.g., in the field, in compost, etc.), burned,or used as fodder or bedding in animal husbandry. Agricultural residuescan be separated from the primary biofuel feedstock during harvesting(e.g., stalks, stems, leaves, etc.) or in post-harvest processing (e.g.,shells, pods, hulls, etc.). In some embodiments, the first fraction ofbiomass may not be used for biofuel production, may not be used for anypurpose, or may represent 0% of the total available biomass. In theseembodiments emissions and sustainability benefits may be credited to theactivity yielding the biomass, to the party arranging for the biomasscarbon sequestration, or to other parties contracting to receive thecredit. Activities yielding the biomass may include, for example,production of conventional agricultural commodities (e.g., of food,feed, and/or fiber products), timber production, land clearingactivities, or other associated activities (e.g., biofuels productionindirectly yielding land clearing activities via price signals onconventional agricultural products)

In general, sequestration mitigates anthropogenic greenhouse gasemission. Sequestration can include any one or more of varioustransportation, processing, and storage steps. Storage can includemonitoring. Sequestration can also include repurposing (e.g., productionof building materials from the biomass, or bio-energy productsubstitution for fossil fuel energy products), for example, where therepurposing mitigates anthropogenic carbon emissions (e.g., buildingmaterials sequester a significant fraction of the biomass carbon on anenvironmentally relevant timescale, substitution of bio-energy productsreduces GHG emission from fossil carbon sources).

Sequestration can include, solely for explanatory purposes, any one ormore of the following steps. However, the number, order, combination,and character of steps will be context specific and depend on a numberof factors, including, for example, biomass type, physicalcharacteristics (e.g., moisture content), chemical characteristics(e.g., volatiles content), dependencies with alternate implementationsof the other principle steps, regulatory factors and requirements (e.g.,regulations specific to particular materials, and monitoringrequirements), and market considerations (e.g., factor prices,assurances, insurance requirements or dependencies). These general stepscan include any one or more of: Biomass collection, Drying, Resizing,Sterilization, Stabilization, Packaging, Sealing, Storage, Monitoring,and Repurposing. Each of these steps is discussed below. Note, however,that the applicability and character of these steps will be contextdependent. In certain applications or for certain purposes one or morestep may be eliminated, combined, disaggregated into or across multiplestages or processes, ordered differently, accomplished at multiplelocations with one or more intermediate transport steps, or integratedinto other processes.

Biomass collection includes the process(es) by which available biomassis aggregated and made available for SPBCS. One example of a potentialbiomass collection system can affect: biomass collection from a fieldand transport to the field edge with mechanized farm implements;subsequent biomass transport from the field edge to a local storage sitevia truck; and subsequent transport to a centralized SPBCS processingfacility via truck. Alternatively, SPBCS processing steps can beaccomplished locally in the field, at the field edge, or at a localstorage site.

Biomass drying includes the process(es) by which moisture is removedfrom the biomass. Biomass drying can support SPBCS implementation byreducing the mass to be transported, processed, and/or stored. Dryingcan enable downstream processing steps, depending on the particularimplementation options selected for those steps. Biomass drying can alsoreduce the potential for biological activity and associated degradationof the biomass, which releases biomass carbon to the atmosphere. Incertain embodiments, drying can be unnecessary, depending on thespecific implementation options selected for other processing steps andstorage. Many technologies can be used for drying biomass, including,for example, air drying before collection in the field, air drying aftercollection at distributed local or centralized facilities, solar dryingsystems, and combustion-heated systems.

Resizing includes the process(es) by which the physical dimensions ofbiomass are altered, to facilitate, enable, or improve othertransportation or processing steps or storage. Resizing could beaccomplished at one or more possible stages, including, for example,pre-collection, pre-transport, pre-drying, pre-sterilization,pre-stabilization, and/or pre-packaging. In certain embodiments,resizing can be unnecessary, depending on the specific implementationoptions selected for other processing steps and storage.

Many technologies may be used for biomass resizing, including, forexample, cutting, shredding, chopping, grinding, chipping, compression,extrusion, baling, and pelletization systems. Various technologies canalso be used that effectively integrate resizing with other steps. Forexample, collection systems can involve biomass resizing, pelletizationcan provide stabilization, and bio-char production via pyrolysis formore advanced carbon stabilization may involve resizing.

Sterilization includes the process(es) by which biological degradationof biomass for SPBCS is controlled by limiting the presence of livingorganisms in or on the biomass. Note that sterilization generally refersto processes that eliminates or kills all forms of life. However, in thecontext of this description, sterilization can also refer to processesthat reduce biological activity to a level sufficient to prevent biomassdecay and associated releases of greenhouse gases. Sterilization couldbe accomplished via a one-time treatment of biomass prior to storage, byperiodic treatments of stored biomass, and/or by continuous, essentiallycontinuous, or periodic treatment of stored biomass. Sterilization canbe accomplished before, during, or after drying, resizing,stabilization, packaging, or storage.

In certain embodiments, sterilization can be unnecessary or deferred forundefined or unlimited periods of time, depending on the specificimplementation options selected for other processing steps. For example,certain storage systems can inherently limit biological activity or canbe engineered to limit biological activity (e.g., mixing with concretes,plastics, foams such as polyethylene, and/or other long-lived solids orliquids). Alternatively, effective monitoring systems can provide forthe implementation of sterilization only for stored biomass exhibitingsigns of potential degradation (e.g., GHG emissions). Sterilization canalso be directly or indirectly integrated with other processing steps.For example, steam dryer systems that effectively convert biomassmoisture into steam can also advance sterilization. Compression orpelletization processes, as well as thermo-chemical transformations, canalso advance sterilization.

Many technologies can be used for biomass sterilization. Thesetechnologies can employ, for example, heat, pressure, chemical, orirradiation. Technologies using heat and/or pressure sterilizationmethods can be used in SPBCS applications. However, the heat and/orpressure can result in thermo-chemical transformations of the biomass,including but not limited to de-volatilization or liquefaction.Sterilization systems employing heat and/or pressure can be integratedwith technologies that harness resulting volatile compounds for theirenergy content (e.g., providing system heat for sterilization andde-volatilization).

Technologies using chemical sterilization methods can be used in SPBCSapplications. These include exposure of biomass to certain gas or liquidphase chemicals before or during biomass storage. For example, biomasscan be exposed to sterilizing compounds in a process unit or thechemicals can be circulated around the biomass while in storage vesselsor enclosures. Many chemical sterilization methods involve oxidizingchemicals. Methods using oxidizing chemicals can require monitoring andmanagement of potential biomass oxidation to limit conversion of biomasscarbon to CO2. Chemicals that can be applied to biomass sterilizationinclude, but are not limited to, ethylene oxide, ozone, hydrogenperoxide, chlorine, or formaldehyde. A wide variety of chemicaldisinfectants or antiseptics can also be used to advance biomasssterilization to the extent required for SPBCS purposes, depending onoptions selected for other principle processes as well as on regulatoryor market requirements.

Technologies using irradiation sterilization methods can be used inSPBCS. These methods include use of gamma radiation, x-ray radiation,and or electron beam processing in a variety of configurations.

Stabilization includes the process(es) by which degradation and/ormobilization of the stored biomass is controlled. Stabilization can beaccomplished in one or more processing stages, in a stand-alone process,or integrated with processes advancing other processing steps. Invarious embodiments, stabilization can be unnecessary, depending on theoptions selected for other processing steps, and on regulatory or marketconsiderations. Stabilization system designs can also reflect regulatoryor market considerations, including the ability to measure andindependently verify quantities and types of stored biomass carbonand/or the ability to extract and repurpose stored biomass.

Many technologies can be used for biomass stabilization. These include,for example, thermo-chemical transformations (e.g., carbonization,torefaction, pyrolysis, hydro-thermal treatments, etc.), physicalprocesses applied to the biomass (e.g., compression, pelletization,briquetting, baling, etc.), and processes that combine biomass withagents that serve to stabilize the biomass carbon (e.g., cement,plastics, foams such as polyethylene foam, or other chemicals).

Packaging includes the process(es) by which biomass is placed into oneor more containment vessels, chambers, wrappings, coatings, or matrixesfor long term storage. Packaging also includes the containment vessels,chambers, wrappings, coatings, or matrixes used for SPBCS applications.Packaging can be accomplished in one or more processing stages, in astand-alone process, or integrated with processes advancing otherprocessing steps. In certain embodiments, packaging can be unnecessary,depending on options selected for other principle processing steps andon regulatory or market considerations.

Many technologies can be used for biomass packaging. These include, butare not limited to, bins, containers, boxes, wrappings (e.g., balewrappings), or silos. Packaging materials include, but are not limitedto, various types of plastic, ceramic, geo-polymer, earth/soil(compacted or not), rock, resin, glass, metal, foam, and variouscombinations thereof. Packaging processes can include: simple dumping orpouring systems, stacking systems (e.g., of compressed biomassaggregates, or of packaging containing biomass solids), mixing andpouring systems (e.g., in the case of biomass stabilization by mixingwith other agents), and/or compression systems. Packaging processes andmaterials can yield in-situ storage vessels or chambers or may yieldpackages suitable for transport to longer term storage facilities (e.g.,that simplify loading into standard shipping containers).

Packaging containment vessels, chambers, and or matrixes can be designedto enable one or more other process steps, including: sterilization(initial and or ongoing), stabilization, sealing, storage, monitoring,and biomass repurposing, including extraction for such repurposing. Forexample, packaging can include combinations of access ports, valves,and/or instrumentation suitable to enable ongoing monitoring andverification of conditions and biomass within containment vessels,chambers, or matrixes, or suitable for periodic or ongoing circulationof compounds for sterilization or stabilization.

Sealing includes the process(es) by which biomass packaging is sealedfor storage (e.g., long term storage). Sealing can be accomplished inone or more independent processes at various stages in the overall SPBCSprocess or can be integrated with processes advancing other principleprocessing steps. For example, sealing can limit gas and liquid exchangebetween the contained biomass and the surrounding environment to advancebiomass containment. Sealing can include combinations of access ports,valves, and/or instrumentation suitable to enable ongoing monitoring andverification of the conditions and of the biomass within containmentvessels, chambers, or matrixes. The access ports and valves can also besuitable for periodic or ongoing circulation of compounds forsterilization or stabilization or can be used to extract and utilize anyproducts of degradation (e.g., biogenic methane). In certainembodiments, sealing can be unnecessary, depending on processing optionsselected for other principle processing steps and on regulatory ormarket considerations.

Many technologies may be used for sealing. These technologies can vary,for example, according to the sealant and/or containment vesselmaterial, and/or containment vessel dimensions, as well as the storageenvironment. The specific choice of sealing technology may alsoinfluence other aspects of SPBCS including, but not limited to:sterilization (initial and or ongoing); stabilization; storage;monitoring; and potential biomass extraction and repurposing.

Storage includes the process(es) by which biomass is disposed of orretained to achieve isolation (e.g., long term isolation) from thenatural environment. Storage can achieve any one or more of thefollowing objectives: (i) preventing release of greenhouse gases; (ii)preventing biomass degradation or mobilization into the broaderenvironment; (iii) enabling verification and monitoring of storedbiomass as well as potential periodic or ongoing sterilizationprocesses; and (iv) enabling utilization of biomass degradation products(e.g., biogenic methane). Storage systems can be closely related toand/or dependent on other principle process steps including, but notlimited to, stabilization, packaging, sealing, monitoring, and potentialrepurposing. Storage systems can be designed to provide particularenvironmental controls and/or to limit the exposure of stored biomass orbiomass packaging to environmental conditions (e.g., extreme temperatureor pressure, excess moisture, chemical or biological agents, or otherpotentially compromising physical processes) that might compromise theobjectives of SPBCS.

Storage systems can include or resemble: conventional land fill disposalsites; relatively smaller scale buried containment vessels or chambers;free standing structures, containment vessels or chambers, eitherenclosed within a larger structure or open to the elements; abandonedmines or mine shafts; abandoned, filled, or partially filled pit minefacilities; or structures submerged in fresh or marine waterenvironments.

Monitoring includes the process(es) that enable any of: measurementand/or control of parameters affecting effective biomass storage;mitigation of undesirable conditions (including potential futureapplications of sterilization/disinfectant processes); and verificationof carbon sequestration benefits. Monitoring can enable potential futureor ongoing verification of carbon sequestration benefits. Monitoring canalso enable accounting of carbon sequestration benefits lost due tobiomass decay/degradation.

Monitoring can include the use of sensors or instruments for measuringtemperature, pressure, chemical/gas composition, moisture/humidity,biological agents and the like. Monitoring can also include collection,monitoring and reporting of, and disposal, combustion or productiveutilization of gases produced from biomass decomposition (e.g., methane)at the containment vessel or larger SPBCS storage facility/site-widescale. Monitoring can include reporting and accounting systems to enablemitigation of undesirable conditions on a site and vessel specific basisand to support quantification and reporting of carbon benefitsretained/lost over time. Furthermore, monitoring can include electricalsystems such as sensors and computers to monitor, generate alarms,generate reports, or perform other functions.

Repurposing includes the process(es) that provide for the option offuture extraction of stored biomass and utilization of the storedbiomass for other purposes (e.g., building or construction materials,bio-energy feedstock). Repurposing can depend upon other steps thatsupport future usability of stored materials. Repurposing can alsoinclude and one or more extraction systems, accounting systems, andreporting systems for carbon benefits gained (e.g., via fossil emissionsdisplaced) or lost/foregone (e.g., sequestration benefits) as a resultof biomass repurposing.

Implementation of SPBCS includes various advantages. At a high level,SPBCS uniquely combines and capitalize on two values embodied inbiomass, embodied atmospheric carbon and embodied solar energy. Forexample, SPBCS quantifies and couples the environmental value ofmitigating anthropogenic GHG emissions to an associated biofuel in thecontext of a regulatory framework. Thus, SPBCS provides a method andeconomic incentive for affecting climate change and other environmentalobjectives that could not have existed prior to the emergence of theregulatory framework. SPBCS can further provide for value from theresulting biomass resource stockpiles from potential future repurposingactivities.

A person of ordinary skill in the art will understand that SPBCS can bereadily implemented under various regulatory frameworks. Illustrativeexamples use three particular regulatory contexts and associated marketsfor carbon dioxide (and other greenhouse gas) emissions, tradableemissions credits, or low carbon fuels: the European Union EmissionsTrading Scheme, the California Low Carbon Fuels Standard, and the U.S.Renewable Fuels Standard.

The European Union Emissions Trading Scheme provides emissionsallowances and tradable credits that can be traded among firms. In thiscontext, SPBCS could be qualified to receive tradable credits inproportion to the quantity of biomass carbon sequestered. Tradablecredits could be issued directly to regulated firms for theirparticipation in SPBCS projects, or could be issued via so calledflexibility mechanisms, including via Joint Implementation as EmissionReduction Units, via Clean Development Mechanism as Certified Emissions,or via International Emissions Trading. Monetary value from such anSPBCS implementation could be generated by reduced compliance cost forregulated firms or through the marketing and sale of tradable creditsissued. Note that this program is similar to what might be expectedunder other so called cap-and-trade type policy instruments.

The Low Carbon Fuel Standard, which is currently being implemented inCalifornia and British Columbia, Canada, and being considered for otherregions, establishes a fuel carbon intensity standard defined generallyin units of mass emissions per unit fuel energy-grams CO2 equivalent permega-joule (gCO2e/MJ), for example. Regulated firms comply with thestandard by submitting an accounting of net fuel emissions per unit offuel energy provided. This accounting enables generation of tradableemissions credits for fuels provided by regulated firms with lifecyclegreenhouse gas emissions intensities lower than the regulatory standard.Regulated firms must meet the standard by increasing supply such lowcarbon fuels and/or acquiring tradable emissions credits from otherfirms supplying such low carbon fuels. As such, tradable emissionscredits issued under this framework are directly associated with thesupply of low carbon fuels produced or supplied. Monetary value fromsuch an SPBCS implementation could be generated by reduced compliancecosts for regulated firms, the ability of firms to effectively offsetemissions associated with relatively high carbon fuels they mightprovide, and/or through the marketing and sale of tradable emissionscredits issued.

The Renewable Fuels Standard specifies quantities of fuels to beprovided to U.S. markets. Quantity targets are specified for severalcategories of fuels. One of the characteristics distinguishing fuelsacross these categories is the lifecycle greenhouse gas emissionsintensity—or carbon intensity—of the fuel. As such, fuels produced withSPBCS implementation in feedstock production could be qualified for afuels category with a lower lifecycle greenhouse gas emissions intensityrequirement. These fuels are expected to command a price premium, whichis a basis for generating monetary value from such an SPBCSimplementation.

Within the context of markets resulting from these and similarregulatory instruments and environments, several potentialimplementation models could be used to support SPBCS. Potentialimplementation models can be differentiated based on the point in thesupply chain responsible for SPBCS implementation.

Implementation by independent operators. SPBCS could be implemented byan independent operator based on the value of resulting tradablecredits. In this case, the SPBCS operator could purchase biomass fromproducers, process and store the biomass, quantify carbon stored,monitor the stored biomass, qualify LCA emissions accounting creditsunder any or all relevant regulatory frameworks, market resultingtradable credits to regulated parties, and account for any and alladjustments resulting from potential future repurposing activities. Onevariant of this case could be for the SPBCS operator to partner with aregulated party with standing under certain regulatory instruments(e.g., a biofuel producer regulated under a low carbon fuels standard)to qualify LCA emissions accounting credits from SPBCS implementation.

Implementation by regulated parties. SPBCS could be implemented by aparty with compliance requirements under one or more relevant regulatoryframeworks (e.g., biofuel producer obligated under a low carbon fuelstandard) based on the value of resulting tradable emissions credits orallowances to the firm or on associated emissions trading markets. Inthis case, the regulated party could purchase biomass for SPBCS jointlywith or independently from their purchases of other biomass feedstock(e.g., agricultural residues along with corn kernels or soybeans forbiofuel production). They could take responsibility for all of theprocesses mentioned above, but would have the additional options ofretaining resulting tradable emissions credits for their own compliancepurposes or marketing them with their other products (e.g., biofuel) toregulated parties downstream in the supply chain in order to benefitfrom potential price premiums for low carbon products.

Implementation by biomass producers. SPBCS could be implemented by abiomass producer. In many cases, resulting implementation models wouldbe analogous to implementation by an independent operator. However,biomass producers implementing SPBCS on biomass resulting as aco-product to primary biomass products (e.g., agricultural residues fromproduction of feedstock for biofuel production) could profit from pricepremiums for primary products associated with lower embodied carbonemissions instead of qualification and sale of tradable emissionscredits. This implementation model could be implemented in a stand-alonemanner by biomass producers or in partnership with independent SPBCSoperators, regulated parties (e.g., biofuel producers), or both toleverage the particular contributions of each party (e.g.,specialization of SPBCS operators and regulatory standing of regulatedparties).

Implementation for secondary values/repurposing. SPBCS can result in aunique combination of two products: biomass-embodied carbon, which issequestered away from the atmosphere, and stockpiles of biomassresources. Stockpiled biomass resources can have a variety of potentialvalues reflecting both conventional values of biomass resources (e.g.,chemical and energy content) and unique temporal and spatial challengesassociated with biomass feedstock supply. For example, the biomasssupply is subject to seasonal variability and to potential disruptionsfrom extreme weather, water, or pest-related events. Moreover, biomasssupply chains are spatially limited from the inherent low density ofproduction (due to inherently distributed solar energy supply) and fromhigh transportation costs. For these and other reasons, the existence oflarge accumulated stockpiles of biomass could provide unique benefits topotential biomass-related projects.

For example, capital financing for a biomass project (e.g., bio-energyproject) can face challenges from feedstock supply disruption risks andconcomitant risks for capital capacity utilization. The availability oflarge biomass stockpiles could effectively insure against such supplydisruptions and thereby enable effective project financing.Alternatively, the existence of large stockpiles can facilitate biomassprojects (e.g., bioenergy projects) simply by concentrating biomassresources over time in a single location. Stockpiles can provide acritical mass of feedstock for launching new biomass projects, or mayprovide resources for periodic processing into other products andservices (e.g., for bio-energy products, biochar soil amendments and thelike) on a rotational basis (e.g., sequentially processing each SPBCSinstallation on an ongoing basis).

In many cases, carbon/climate benefits lost or foregone or traded (e.g.,trading benefits of carbon sequestered for benefits of energy productsubstitution) due to biomass reprocessing/repurposing will need to beaccounted for under appropriate regulatory frameworks (e.g., theframeworks that provided the carbon benefits that motivated SPBCSimplementation). However, the quantity of foregone or traded carbonbenefits and their value will depend on the particularreprocessing/repurposing options employed and potentially on theprevailing prices for tradable emissions credits at the time ofreprocessing/repurposing. For example, biomass utilization ininfrastructure projects or building materials (e.g., as a component inconcrete or other building material) can effectively retain full orpartial carbon benefits from SPBCS implementation. Alternatively, abio-energy project, including projects that co-utilize biomass withfossil fuels (e.g., co-utilization of coal and biomass for heat, power,and/or fuels production), incorporating CO2 capture and storage ingeologic formations (CCS) can retain 90% or more of carbon sequestrationbenefits from SPBCS implementation and add energy product substitutionbenefits. A bio-energy project, including projects that co-utilizebiomass with fossil fuels (e.g., co-utilization of coal and biomass forheat, power, and/or fuels production), that does not include CCS willlikely forego benefits of carbon sequestration from certain SPBCSimplementation, but can provide energy product substitution benefits.However, the value foregone or traded can be limited by, among otherthings, the relative availability of other low cost options formitigating anthropogenic greenhouse gas emissions (e.g., other low costoptions may emerge that decrease the value of sequestration benefits orallow for CCS at reasonable cost, or low emission substitutes forcertain energy products may not emerge, increasing the relative value ofsubstitution benefits from bio-energy products) or less stringent futureemissions targets.

EXAMPLES Low CI Corn Ethanol Under the California Low Carbon FuelsStandard, Methods of Engineering a Biofuel Cycle and Accounting forCarbon Flows and Determining a Regulatory Value for a Biofuel Example 1Low CI Corn Ethanol Under the California Low Carbon Fuels Standard

The California Low Carbon Fuels Standard represents one opportunity forimplementing SPBCS. Under this standard, a biofuel producer couldsponsor SPBCS implementation with the stover resulting from corn ethanolfeedstock production and/or biomass resulting from other crops in thecorn rotation. Analogous implementations, for example, could includethose by biodiesel producers storing residues from soybean production.In the case of implementation by a corn ethanol producer, the ethanolproducer could submit a new corn ethanol production pathway for approvalby the California Air Resources board that reflects the implications ofSPBCS implementation for lifecycle fuel carbon intensity. Approval ofsuch a production pathway could yield issuance of additional tradablecarbon credits for corn ethanol produced according to the new productionpathway in proportion to the quantity of biomass stored via SPBCS. Thesetradable credits could be retained for the producer's compliancepurposes, sold with their product ethanol to regulated partiesdownstream in the supply chain (e.g., fuel blenders), or sold to otherregulated parties.

The biofuel can be produced from a first fraction of a biomass accordingto the various methods known in the art (e.g., wet mill or dry mill cornethanol). Sequestration of a second fraction of the biomass (e.g.,agricultural residue, including corn stover) can be accomplished by anumber of steps known in the art, including but not limited to, theexample outlined in Table 1. The manner in which SPBCS mitigatesanthropogenic carbon emissions through engineering a biofuel carboncycle is discussed, for example, in connection with Examples 2-4 below.A regulatory value for the biofuel can be calculated according to theregulatory framework, which is discussed, for example, in connectionwith Examples 4-7 below.

TABLE 1 Biomass collection Mechanized stover collection in large roundbales Drying Air drying on the field or field edge to ~15% moistureResizing Chopping or grinding at the field edge or at a nearby facilitySterilization Irradiation at a nearby facility, if necessaryStabilization Pelletization or compression into blocks, if necessaryPackaging Dumping and compression of resized or pelletized stover or bystacking of compressed stover blocks at a purpose-built landfill typefacility Sealing Clay and plastic liners and covers Storage In thededicated landfill type facility Monitoring (optional) Temperature,pressure, and moisture sensors as well as methane gas collection,measurement, and combustion/utilization systems Repurposing (optional)Removal of the landfill cover and mechanized extraction of storedbiomass (e.g., front loaders and dump trucks) for utilization incellulosic ethanol production systems

FIG. 1 shows biogenic carbon flows or carbon cycle in an example ofconventional corn ethanol production and use. FIG. 1 is usefulcomparison for FIGS. 2-4, which illustrate examples of engineering acarbon cycle in the context of SPBCS to mitigate anthropogenicgreenhouse gas emissions. FIGS. 2-4 also illustrate examples of carboncycle components that can be used in determining a regulatory value thataccounts for the carbon intensity and/or sustainability of a biofuel.The following examples can be mapped onto the process schematics shownin FIGS. 5 and 6, and algorithms discussed in connection with Tables2-4, and analyzed to determine a regulatory value for a biofuel. Theseexamples, together with the disclosure, also provide a framework anduseful examples for applying the invention in the context of additionaland/or future regulatory frameworks.

The carbon cycle shown in FIG. 1 can be considered to begin whenbiogenic carbon is fixed from the atmosphere via photosynthesis. Theportion of the fixed carbon embodied in primary biofuel feedstock (e.g.,corn kernels) is transported to an ethanol production facility.Separately, the portion of the fixed carbon embodied in agriculturalresidues is subject to natural degradation and decomposition, throughwhich it is returned to the atmosphere. Ethanol is produced at theproduction facility from the primary biofuel feedstock. A portion ofprimary biofuel feedstock carbon is released to the atmosphere duringethanol production (e.g., via fermentation off-gases), while the balanceis converted into biofuel (e.g., ethanol) and biofuel productionco-products (e.g., animal feed, vegetable oils, and/or biodiesel). Then,the ethanol and ethanol production co-product(s) are used, and thebiogenic carbon in the biofuel and biofuel production co-products isreturned to the atmosphere. In some cases this return of biogenic carbonto the atmosphere can be direct (e.g., in the case of biofuelcombustion) or indirect (e.g., in the case of animal feed co-productuse).

Note that the figures focus on biogenic carbon flows in order toillustrate a principle of SPBCS. However, other flows of greenhousegases are relevant to the biofuel carbon cycle and accounting for carbonflows and determining a regulatory value for a biofuel. For example,while regulatory values can be calculated solely from biogenic carbonflows, in many cases a consideration of carbon flows from fossilhydrocarbon sources (e.g., petroleum, coal, and the like) can beimportant in calculating a regulatory value. Examples of other relevantflows are discussed in connection with FIGS. 2-6 and Tables 2-4.

Example 1 SPBCS with Residue Transportation, Processing, and Storage

FIG. 2 shows biogenic carbon flows in an example of SPBCS in cornethanol production, where the carbon cycle is engineered to includeresidue collection, transportation, processing, and storage. The storageof solid phase biomass carbon can prevent the emission of GHG bypreventing the degradation of the solid phase biomass carbon. Thus, thisexample shows one way to engineer a carbon cycle to mitigateanthropogenic carbon emissions (e.g., in one sense, carbon from humanactivity is prevented from flowing to the atmosphere in gaseous form; inanother sense, a renewable and low CI biofuel displaces the use of afossil fuel, thereby reducing the CI of the human activity).

In FIG. 2, the fixing of biogenic carbon from the atmosphere, as well asthe production and use of ethanol can be essentially the same as shownand described in connection with FIG. 1. A second fraction of theagricultural biomass (e.g., comprising agricultural residue), whichembodies biogenic carbon, is transported for processing and, ultimately,storage. In this example, processing is employed to improve storage(e.g., to increase efficiency by making the residue easier to transportand store, and to decrease emissions by making the residue lesssusceptible to degradation). Storage can be continued indefinitely, orfor another time scale relevant to the climate change or policyobjective.

The second fraction of the agricultural biomass does not necessarilyinclude all of the biomass that is not used for biofuel production(e.g., the balance of the corn plant after separation from the cornkernels). For example, some agricultural residue can be left in thefield to support soil fertility, erosion protection, and otheragricultural objectives. Such residue would be subject to naturaldegradation and decomposition processes, through which embodied carbonis returned to the atmosphere. This carbon flow is indicated with adashed line to reflect its secondary impact in differentiating netcarbon flows relative to those indicated in FIG. 1.

Example 2 SPBCS with Residue Transportation, Processing, and Storage

FIG. 3 shows biogenic carbon flows in an example of SPBCS in cornethanol production, where the carbon cycle is engineered to includeresidue transportation, processing, and storage. FIG. 3 is a variationon FIG. 2, with additional indicia for carbon flows to the atmospherefrom residue processing and storage.

In various embodiments, the residue processing can produce GHG emissionsthat should be accounted for in the corresponding biofuel's regulatoryvalue. For example, heating the agricultural residue (e.g., to reducemass, increase stability, and/or sterilize) can release GHG to theatmosphere. Similarly, processing by pyrolysis (e.g., to produce astable bio-char or bio-coal) can release GHG to the atmosphere.Likewise, storage can produce GHG emissions that should be accounted forin the corresponding biofuel's regulatory value. Emissions from storagecan be a result of natural process and/or repurposing.

Example 3 SPBCS with Agricultural Residue Co-Products

FIG. 4 shows biogenic carbon flows in an example of SPBCS in cornethanol production, where the carbon cycle is engineered to includeagricultural residue co-products. FIG. 4 is a variation on FIG. 3, withadditional indicia for carbon flows to the atmosphere from residueco-products. In various embodiments, residue co-products can includeresidue processing by pyrolysis to produce heat, power, electricity,and/or fuels with sequestration of associated biochar). Depending on thespecific residue processing technologies employed, some additionalco-products may be produced along with solid phase biomass carbon forlong term storage. In various embodiments, use of these co-products canresult in additional GHG emissions (e.g., bio-oil combustion) or no GHG(e.g., electricity).

Example 4 Process Schematics for Lifecycle Emissions Accounting

The components of a SPBCS carbon cycle can be represented as processschematics. Such schematics can facilitate the conceptualization and/ormapping of a biofuel carbon cycle (e.g., including a fuel pathway) to anaccounting system. In this example FIG. 5 shows a process schematic forlifecycle emissions accounting (e.g., related to FIG. 1 and Table 2) andFIG. 6 shows a process schematic for lifecycle emissions accounting forSPBCS corn ethanol (e.g., related to FIGS. 2-4 and Tables 3 and 4).

The schematic in FIG. 5 is adapted from FIG. 1 of the California AirResources Board “Detailed California-Modified GREET Pathway for CornEthanol,” which describes the lifecycle components used to define thelifecycle greenhouse gas emissions from corn ethanol production and todefine the regulatory default value of carbon intensity to be applied tocorn ethanol fuels under the California Low Carbon Fuel Standard. Suchregulatory default values provide a baseline for a particular biofuel(e.g., ethanol with a carbon intensity=x). Entities would then have anenvironmental and economic incentive to engineer and/or characterize abiofuel carbon cycle that results in a biofuel with a more favorableregulatory value (e.g., ethanol with a carbon intensity <x, though therelationship may vary depending upon the metric of sustainability/CI andaccounting convention).

FIG. 6 shows an example process schematic for lifecycle emissionsaccounting for SPBCS corn ethanol. This schematic illustrates lifecyclecomponents used to describe the lifecycle greenhouse gas emissions fromSPBCS corn ethanol. One difference between this schematic and FIG. 5 isthe column of lifecycle components on the left side of the figure, whichdescribe processes associated with harvest, transport, residue storage &processing, and solid phase biomass carbon storage. Note that FIGS. 5and 6 provide one convenient format for illustrating these lifecyclecomponents, which can be alternatively illustrated with greater or fewerlifecycle components. Other formats are conceivable and would likely berequired in other regulatory contexts. A person with ordinary skill inthe art could adapt the present examples to other formats forillustrating, conceptualizing, and quantifying the lifecycle componentsand emissions from SPBCS. Such adaptations are included in SPBCS.

One feature of various embodiments of SPBCS is the inclusion ofcomponents describing the transportation, processing, and/or storage ofagricultural residues that are produced as a consequence of biofuelfeedstock cultivation (crop cultivation in the present example), forpurposes that generate lifecycle emissions accounting credits within thebiofuel lifecycle greenhouse gas emissions accounting schematic. Noincentives existed for SPBCS, or the concept of developing new sourcesof lifecycle emission accounting credits, before the emergence ofregulatory frameworks such as the EU-ETS and no incentives existed fordeveloping new sources of lifecycle emissions accounting credits withinfuel supply chains before fuel-specific regulatory frameworks including:U.S. RFS2; LCFS currently implemented in CA and BC, and beingcontemplated for WA, OR, and NEMA regions; EU-RED and FQD; and UK-RTFO.

Given a biofuel or biofuel carbon cycle, there are a number of ways toaccount for carbon flows and determine a regulatory value for thebiofuel. In jurisdictions having an established regulatory system, aperson of ordinary skill in the art would understand that they couldfirst look to the established regulatory system for guidance indetermining an applicable methodology. However, it is also understoodthat such systems are generally based upon quantifying relevantcomponents of the biofuel carbon cycle and accounting for the relevantcomponents to arrive at a net carbon intensity and/or sustainabilitymeasure for the biofuel.

The quantification of relevant carbon cycle components can be in termsof units of greenhouse gas per units of energy (e.g., gCO2e/MJ). Theaccounting methodology can be, for example, system expansion orallocation. In system expansion, lifecycle emissions accounting creditsare provided for net emissions reductions associated with use of thevarious products as a substitute for more conventional products. Underallocation methodologies, a fraction of lifecycle emissions (generallyemissions associated with processes upstream of the material diversionfor co-product use) are allocated to the various products (see, e.g.,Examples 6 and 7).

Example 5 Greenhouse Gas Emissions Summary for Corn Ethanol Baseline

Table 2 shows a greenhouse gas emission (GHG) accounting summary for dryand wet mill corn ethanol. This summary serves as a baseline for theSPBCS examples shown in Table 3 and 4. This summary is adapted from theCalifornia Air Resources Board 2009 “Detailed California-Modified GREETPathway for Corn Ethanol,” where the derivation of the values isprovided in detail.

TABLE 2 Corn Ethanol Fuel Dry Mill Wet Mill Cycle Components GIIG(gCO2/MJ) GIIG (gCO2/MJ) Well-to-tank Crop Cultivation 5.65 5.81Chemical Inputs to Cultivation 30.2 31.35 Corn Transportation 2.22 2.28Ethanol Production 38.3 48.78 Ethanol Transport & Storage 2.7 2.63Ethanol Production Co-products −11.51 −16.65 Total well-to-tank 67.674.2 Tank-to-wheel Ethanol Combustion 0 0 Total tank-to-wheel 0 0 Totalwell-to-wheel 67.6 74.2

In this example, the regulatory value for dry mill corn ethanol is 67.6gCO2/MJ and the regulatory value for wet mill corn ethanol is 74.2gCO2/MJ. The accounting shown in Table 2 (as well as Tables 3 and 4)reflects direct emissions only. Additional emissions factors forindirect emissions (e.g., indirect land use change) can also be includedwithin an accounting framework, as can other combinations of directemissions. For example, additional emissions factors or other accountingmay also be included to represent increased fertilizer requirements tocompensate for nutrients removed with agricultural residues. In examples5-7, the Ethanol Combustion values assume all carbon in the fuel itselfis biogenic and therefore do not represent a net emission to theatmosphere.

Example 6 GHG Summary for Corn Ethanol SPBCS, System ExpansionMethodology

Table 3 shows a greenhouse gas emissions summary for dry and wet millcorn ethanol for a SPBCS methodology.

TABLE 3 Corn Ethanol Fuel Dry Mill Wet Mill Cycle Components GHG(gCO2/MJ) GHG (gCO2/MJ) Well-to-tank Crop Cultivation 5.65 5.81 ChemicalInputs to Cultivation 30.2 31.35 Corn Transportation 2.22 2.28 EthanolProduction 38.3 48.78 Ethanol Transport & Storage 2.7 2.63 EthanolProduction Co-products −11.51 −16.65 Residue Harvest & Storage 1.70 1.74Residue Transportation 2.22 2.28 Residue Storage & Processing 0 0Residue Carbon Storage −93.4 −90.0 Total well-to-tank −21.9 −11.7Tank-to-wheel Carbon in fuel 0 0 Total tank-to-wheel 0 0 Totalwell-to-wheel −21.9 −11.7

In this example, the regulatory value for dry mill corn ethanol is −21.9gCO2/MJ and the regulatory value for wet mill corn ethanol is −11.7gCO2/MJ. In comparison to Example 5, SPBCS provides a significantbenefit in terms of providing the corn ethanol with a more favorableregulatory value than the baseline. Thus, the environmental andaccounting value of Residue Carbon Storage is large (e.g., dominates thecalculation of the regulatory value) and the environmental andaccounting cost of terms such as Residue Harvest & Storage, ResidueTransportation, and Residue Storage & Processing is small (e.g., lessthan that of biofuel production and little effect on the regulatoryvalue).

In this Example, the Residue Harvest & Storage value assumes thatresidue harvest requires 30% of the energy required (yielding 30% of theGHG emissions) for crop cultivation (e.g., corn farming) and has zerostorage losses. The Residue Transportation value assumes thattransportation emissions are equal to those for transporting the corn,based on 1:1 mass ratio (see below). However, emissions could besubstantially higher (e.g., due to substantially lower density ofstover, which could be mitigated by processing the agricultural residue)as well as differences in transportation mode (e.g., vehicle type,distance, and the like) and/or distance (in the case that biofuel andresidue processing facilities are not co-located).

Residue Storage & Processing value assumes exothermic hydrothermaltreatment yields zero net GHG emissions and transforms 100% of residuebiomass carbon into resulting “bio-coal” for sequestration. ResidueCarbon Storage value assumes 100% of carbon in removed residues iseffectively sequestered (no storage losses, processing losses, orleakage from storage facilities), calculated using the computationalalgorithm as specified in Table 3.

Example 7 Computational Algorithm for Defining Lifecycle EmissionsAccounting Credits Produced Via SPBCS, Applied in the Context of theCalifornia Low Carbon Fuel Standard SPBCS, System Expansion Methodology

Table 4 shows an example of computational algorithm for defininglifecycle emissions accounting credits produced by SPBCS applied in thecontext of the California Low Carbon Fuel Standard. The Carbon intensityreduction reflects the amount of solid phase biomass carbon sequestered.The Carbon intensity reduction from SPBCS values shown in Table 5 werecalculated according to the following methodology.

TABLE 6 Dry Wet Parameter Mill Mill Units Stover carbon content 0.5 0.5kgC/kg(stover) [% wt, dry] Stover:kernal mass ratio 1 1 kg(stover)/kg(kernel) Fraction of stover utilized 0.5 0.5 kg(stover removed)/kg(stover produced) Corn kernel mass (dry) 21.5 21.5 kg/bu Corn ethanolyield 2.62 2.72 gal/bu Ethanol heat content 76330 76330 btu/gal CO2:Cmass ratio 3.67 3.67 gCO2/gC Energy unit conversion factor 947.8 947.8btu/MJ Mass unit conversion factor 1000 1000 g/kg Algorithm outputCarbon intensity reduction from 93.4 90.0 gCO2/MJ(eth) SPBCS

In this example, the reduction in regulatory value for dry mill cornethanol is 93.4 gCO2/MJ and the reduction in regulatory value for wetmill corn ethanol is 90.0 gCO2/MJ. These values are used in Example 6.

In Example 7, the Assumptions are defined as follows: Stover:kernel massratio defines the ratio of corn stover yield to corn kernel yield on adry mass basis; Fraction of stover removed defines the fraction of cornstover removed from the field, with the remainder assumed to be left inplace to advance erosion protection, soil fertility, and otheragricultural objectives; Corn kernel mass (dry) defines the mass of abushel of corn kernels; Corn ethanol yield defines the ethanol producedper bushel of corn kernels; Ethanol heat content defines the heatingvalue of anhydrous ethanol produced—a lower heating value is used hereto be consistent with the standard applied under the California LowCarbon Fuel Standard; CO2:C mass ratio is used to convert between massunits of carbon and carbon dioxide, it is defined as the ratio of themolecular weights of the carbon in carbon dioxide (44/12). Energy unitconversion factor is used to convert between Imperial and metric unitsof measure for fuel heat content (btu or British thermal units and megajoules, respectively). Mass unit conversion factor is used to convertunits of mass from kilograms to grams, it is defined as the number ofgrams in a kilogram (1000)

In Example 7, the algorithm output is the product of all of the factorslisted under “Assumptions” above, except “Corn Ethanol Yield” and“Ethanol Heat Content”, the inverses of which are multiplied by theproduct of the other factors in the algorithm. Example 7 shows one ofmany possible implementations of the algorithm. Other implementationscould be applied within the context of the California Low Carbon FuelStandard, and other implementations would almost certainly be requiredto utilize the invention in the context of fuel policies in otherjurisdictions (e.g., BC LCFS, UK RTFO and EU RED and FQD). In these andother embodiments, loss factors could be applied or other means ofaccounting for carbon losses and/or GHG emissions from residue carbonlosses due to degradation during Residue Storage, transport, and thelike. Differences in GHG emissions from biomass transport, due to aprocess implementation warranting alternate assumptions, for example,would need to be reflected. Any fossil greenhouse gas emissions fromResidue Processing or Residue Carbon Storage operations would also needto be included in the algorithm.

While the technology has been particularly shown and described withreference to specific embodiments, it should be understood by thoseskilled in the art that various changes in form and detail may be madewithout departing from the spirit and scope of the technology as definedby the appended claims.

1. A computerized method of using a data processor having a memory toaccount for carbon flows and determine a regulatory value for a biofuel,the method comprising: storing, by the data processor, in memory, one ormore first values characterizing carbon flows associated with theproduction and use of the biofuel, wherein the biofuel is derived from afirst fraction of an agricultural biomass comprising sugar cane orsoybean; storing, by the data processor, in memory, one or more secondvalues characterizing carbon flows associated with sequestration ofsolid phase biomass carbon, wherein the solid phase biomass carbon isderived from a feedstock residue of the agricultural biomass and whereinthe sequestration of the solid phase biomass carbon mitigatesanthropogenic greenhouse gas emission; calculating, using the dataprocessor, the regulatory value for the biofuel from the first valuesand the second values; and qualifying the biofuel as compliant with aregulatory framework using the regulatory value.
 2. The method of claim1 further comprising qualifying the biofuel for a fuels category with alower lifecycle greenhouse gas emissions intensity requirement.
 3. Themethod of claim 1 further comprising qualifying the biofuel in theregulatory framework as a fuel with a lower lifecycle greenhouse gasemissions intensity.
 4. The method of claim 1 wherein the regulatoryframework is the U.S. Renewable Fuels Standard, the California LowCarbon Fuels Standard or the European Union Emissions Trading Scheme. 5.The method of claim 1, wherein the sequestration comprises processing tomitigate degradation of the solid phase biomass carbon.
 6. The method ofclaim 1, wherein processing comprises one or more of collection, drying,resizing, sterilization, stabilization, packaging, and sealing.
 7. Themethod of claim 1, wherein the sequestration comprises storing the solidphase biomass carbon to mitigate environmental interaction.
 8. Themethod of claim 1, further comprising monitoring carbon flow from thesequestered solid phase biomass carbon.
 9. The method of claim 1,further comprising repurposing the sequestered solid phase biomasscarbon.
 10. The method of claim 1 further comprising: generating atradable credit from the regulatory value for the biofuel; and tradingthe biofuel having the tradable credit.
 11. A method of engineering acarbon cycle for production and use of a biofuel, comprising: arrangingproduction of the biofuel by a first generator, the biofuel producedfrom biofuel feedstock of an agricultural biomass comprising sugar caneor soybean; arranging sequestration of solid phase biomass carboncomprising solid phase biomass carbon, by a storage system, fromfeedstock residue of the agricultural biomass, thereby mitigatinganthropogenic greenhouse gas emission; and assigning to the biofuel aregulatory value based at least in part upon a first set of one or moreemissions credit values characterizing production and use of the biofueland a second set of one or more emissions credit values characterizingthe sequestration.
 12. The method of claim 11 further comprisingqualifying the biofuel as compliant with a regulatory framework.
 13. Themethod of claim 11 further comprising qualifying the biofuel for a fuelscategory with a lower lifecycle greenhouse gas emissions intensityrequirement.
 14. The method of claim 11 further comprising qualifyingthe biofuel in the regulatory framework as a fuel with a lower lifecyclegreenhouse gas emissions intensity.
 15. The method of claim 12 whereinthe regulatory framework is the U.S. Renewable Fuels Standard, theCalifornia Low Carbon Fuels Standard, or the European Union EmissionsTrading Scheme.
 16. The method of claim 11, wherein the sequestrationcomprises processing to mitigate degradation of the solid phase biomasscarbon.
 17. The method of claim 11, wherein the sequestration comprisesstoring the solid phase biomass carbon to mitigate environmentalinteraction.
 18. The method of claim 11, further comprising monitoringcarbon flow from the sequestered solid phase biomass carbon.
 19. Themethod of claim 11, further comprising repurposing the sequestered solidphase biomass carbon.
 20. The method of claim 11, further comprising:generating a tradable credit from the regulatory value for the biofuel;and trading at least one of the biofuel having the tradable credit andthe tradable credit.
 21. A method of manufacturing a biofuel,comprising: producing, by a generator, the biofuel from biofuelfeedstock of an agricultural biomass comprising sugar cane or soybean;sequestering, by a storage system, solid phase biomass carbon fromfeedstock residue of the agricultural biomass, wherein sequestrationmitigates anthropogenic greenhouse gas emission; and assigning to thebiofuel a regulatory value based at least in part upon a first set ofone or more emissions credit values characterizing production and use ofthe biofuel and a second set of one or more emissions credit valuecharacterizing the sequestration.
 22. The method of claim 21 furthercomprising qualifying the biofuel as compliant with a regulatoryframework using the regulatory value.
 23. The method of claim 21 furthercomprising qualifying the biofuel in the regulatory framework as a fuelwith a lower lifecycle greenhouse gas emissions intensity.
 24. Themethod of claim 21 further comprising qualifying the biofuel for a fuelscategory with a lower lifecycle greenhouse gas emissions intensityrequirement.
 25. The method of claim 22 wherein the regulatory frameworkis the U.S. Renewable Fuels Standard, the California Low Carbon FuelsStandard, or the European Union Emissions Trading Scheme.
 26. The methodof claim 21, wherein the sequestration comprises processing to mitigatedegradation of the solid phase biomass carbon.
 27. The method of claim21, wherein the sequestration comprises storing the solid phase biomasscarbon to mitigate environmental interaction.
 28. The method of claim21, further comprising monitoring carbon flow from the sequestered solidphase biomass carbon.
 29. The method of claim 21, further comprisingrepurposing the sequestered solid phase biomass carbon.
 30. The methodof claim 21, further comprising generating a tradable credit from theregulatory value for the biofuel.
 31. The method of claim 30, furthercomprising selling or marketing at least one of the biofuel and tradablecredit.
 32. The method of claim 30, further comprising retaining thetradable credits.
 33. The method of claim 30, further comprisingmarketing or selling the tradable credits to a regulated party.
 34. Themethod of claim 33, wherein the regulated party is located downstream inthe supply chain.